What is the main chemical compound in limestone?

What is the correct chemical name for the substance more commonly known as ‘quicklime’?

What is the correct balanced symbol equation for the formation of solid slaked lime?

• CaO(s) + H₂O(l) → Ca(OH)₂(aq)

• CaO(s) + H₂O(l) → Ca(OH)₂(s)

• CaO(s) + H₂O(l) → 2CaOH₂(s)

Which of the following is a use of limestone?

• Heating with cement to make clay

• Removal of impurities from the blast furnace

• Neutralising alkaline soil for agriculture

Which of the following is an economic advantage of limestone quarrying?

• News jobs created for the local population

• Improved transport links

• An artificial barrier from natural materials around the quarry to minimise noise pollution

Which of the following effects of quarrying is an environmental disadvantage?

• The extra traffic and noise pollution would make nearby settlements less desirable to live in

• Quarrying destroys the natural landscape and any wildlife habitats within the area

• The dust and the pollution from the extra traffic could cause health problems

Copper carbonate is a green solid which can be thermally decomposed easily by heating it with a Bunsen burner. The green colour disappears and a black solid is formed. A colourless gas is also formed. What is the black solid that is formed?

Copper carbonate is a green solid which can be thermally decomposed easily by heating it with a Bunsen burner. The green colour disappears and a black solid is formed. A colourless gas is also formed. Which test would you use to confirm the identity of this gas along with the expected result?

• Put a glowing splint into a test tube filled with this gas - the glowing part of the splint will re-ignite

• Place the flame of a lighted splint into a test tube of this gas - the gas will ignite with a squeaky pop

• Bubble the gas through limewater- the limewater will turn milky

Why does copper carbonate decompose at a much lower temperature than potassium carbonate?

• Potassium is a less reactive metal than copper

• There are twice as many potassium atoms than there are copper atoms, so twice as much heat energy is required

• Potassium is more reactive than copper

When a small amount of water is added to a solid piece of calcium oxide, it crumbles to form a powdery white solid of calcium hydroxide. During the reaction it fizzes, and it appears that a small amount of white ‘smoke’ rises from the reaction whenever you add a drop of water. How would you explain these observations?

• This is a highly exothermic reaction so the heat energy released boils the water from steam

• This reaction also forms a white gas as part of the reaction and looks like smoke

• This is a highly endothermic reaction and so the heat energy absorbed causes water vapour in the air to condense